* {
    margin: 0;
    padding: 0;
}

body{ background-image:url(../images/bg.jpg);background-size:100%;}

#game_object {
    background-color: #ffffff;
    height: 900px;
    margin: 20px auto;
    position: relative;
    width:900px;
}
#board div {
    background: url("../images/cat_face.jpg") no-repeat scroll 0 0 #ffffff;
    cursor: pointer;
    height: 300px;
    line-height: 300px;
    position: absolute;
    text-align: center;
    width:300px;

    /* css3 shadow */
    -moz-box-shadow: inset 0 0 20px #555555;
    -webkit-box-shadow: inset 0 0 20px #555555;
    -ms-box-shadow: inset 0 0 20px #555555;
    -o-box-shadow: inset 0 0 20px #555555;
    box-shadow: inset 0 0 20px #555555; 
}